Aquarium base



FIG. 1 is a top plan view of an aquarium base showing my new design;

FIG. 2 is a reduced bottom plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a left side elevational view thereof; and,

FIG. 6 is a right side elevational view thereof.

The ornamental design for an aquarium base, as shown and described.